hear it again

: the chief character in a play, novel, or story

Example sentence:
My favorite part of the book was when the protagonist slipped past the dragon while it tried to set fire to the buzzing mosquitoes.

Etymology:
The prefix "ant-" comes from the Greek "anti," meaning "against." An antagonist is one who opposes, or is against, another. The prefix "prot-" in "protagonist," on the other hand, comes from the Greek word "pro," meaning "before, forward." The second element in both words comes ultimately from the Greek word "agon," meaning "contest." You can think of a story's protagonist and antagonist as competitors in a contest. As the story progresses, the protagonist tries to move forward, while the antagonist opposes the protagonist's effort.